| (19) |
 |
|
(11) |
EP 0 227 235 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
30.03.1988 Bulletin 1988/13 |
| (43) |
Date of publication A2: |
|
01.07.1987 Bulletin 1987/27 |
| (22) |
Date of filing: 15.10.1986 |
|
|
| (84) |
Designated Contracting States: |
|
ES FR GB GR IT |
| (30) |
Priority: |
16.12.1985 US 809440
|
| (71) |
Applicant: INTERNATIONAL MINERALS AND CHEMICAL CORPORATION |
|
() |
|
| (72) |
Inventors: |
|
- Michalski, Dennis H.
()
- Srinivasan, Viswanathan
()
|
|
| |
|
| (54) |
Process of removing cationic impurities from wet process phosphoric acid |
(57) A method of removing aluminum, magnesium, iron and other impurities from wet process
phosphoric acid is provided. The method comprises partially ammoniating the acid and
reacting the acid with a fluoride ion donating compound to precipitate aluminum- and
magnesium-containing ralstonite and ammonium fluorosilicate which can be easily separated
from the acid thereby producing a partially ammoniated wet process phosphoric acid
of reduced impurities content.